1. Field of the Invention
The present invention relates to a gas generator for an air bag disposed in a vehicle and preferably used to protect a passenger from an impact, and to an air bag apparatus using the gas generator.
2. Description of the Related Art
An air bag apparatus is mounted in an automobile and the like to protect a passenger from an impact at the time of a collision. The air bag apparatus is formed to rapidly generate a gas by an actuation of a gas generator for an airbag, there by expanding the air bag (bag body).
Generally in the gas generator, when ignition means is actuated by the impact, a gas generating agent is ignited and burnt to generate a high temperature and high pressure gas, and the generated gas is ejected from a gas discharging port into the air bag (bag body).
Conventionally, the ignition means only comprises an igniter actuated by an actuating signal, or comprises a combination of the igniter and a transfer charge adapted to be ignited and burnt by the actuated igniter.
A combustion chamber in which the gas generating agent is accommodated is variously designed depending upon a shape of a housing, a layout of necessary constituent members and the like, and as to the gas generating agents charged therein, there are various shapes and compositions.
A combustion state of the gas generating agent is an important design factor for adjusting an operation performance of the gas generator. Therefore, it is preferable that the gas generating agent is effectively and reliably ignited and burnt by the actuation of the ignition means.
However, the conventional gas generator is still susceptible to improvements for enhancing the ignition performance of the gas generating agent.
The amount of the gas generating agent used in the gas generator is also an important factor for adjusting the operation performance of the gas generator. Usually, the gas generating agent is charged in the combustion chamber, so that it is necessary to adjust the capacity of the combustion chamber in order to adjust the amount of the gas generating agent.
Further, in a conventional gas generator having two combustion chambers in the housing, the gas generating agent is charged in each of the combustion chambers. In order to obtain an optimal operation performance, the gas generator is formed such that igniting timing of the gas generating agent in each of the combustion chambers can be adjusted. In such a gas generator, it is preferable that the combustion of the gas generating agents accommodated in each combustion chamber can independently be adjusted, and it is necessary that the gas generator can easily be produced and a size thereof is reduced.